Monofilament dental tapes traditionally have focused on improving their primary consumer benefits of reduced “shredding” and reduced breakage during flossing while falling short on a range of product attributes generally associated with various releasable coatings applied to these monofilament tapes. These coating-related attributes included: hi-impact flavor, mouth feel, cleaning and “hand” of the coated tape. These attributes generally require coatings at from between about 20% by weight of the monofilament tape and about 120% by weight of the tape.
Monofilament interproximal devices are described and claimed in: U.S. Pat. Nos. Re 35,439; 3,800,812; 4,974,615; 5,760,117; 5,433,226; 5,479,952; 5,503,842; 5,755,243; 5,845,652; 5,884,639; 5,918,609; 5,962,572; 5,998,431; 6,003,525; 6,083,208; 6,148,830; 6,161,555; and 6,027,592, the disclosures of which are hereby incorporated herein by reference. These dental tapes generally have serious shortcomings in gentleness, in delivering coatings during flossing and in being handled easily and conveniently during flossing.
Polytetrafluoroethylene (PTFE) based interproxunal devices are described in: U.S. Pat. Nos. 5,209,251; 5,033,488; 5,518,012; 5,911,228; 5,220,932; 4,776,358; 5,718,251; 5,848,600; 5,878,758; and 5,765,576. To date, no commercial versions of these tapes have been coated effectively and cannot be used to deliver active ingredients, interproximally and subgingivally during flossing. Handling during flossing Is difficult. Most have to be folded to provide a consumer acceptable edge. Many are plagued with serious dimensional inconsistency problems, as well.
Most monofilament tapes and particularly the PTFE tapes are difficult to coat with “releasable coatings” at these relatively high levels, particularly when the coatings are required to be substantially free from flaking. Copending Provisional Application Ser. No. 60/263,220 is directed to crystalline-free releasable coatings for PTFE and other monofilament tapes that are substantially free from flaking. The teachings of this application are incorporated herein by reference.
Heretofore, coatings for dental flosses and dental tapes have traditionally been comprised of microcrystalline wax and a small amount of flavor. Occasionally trace amounts of “active ingredients” such as fluoride, CPC or triclosan are added. The content of each of these additives in the coating is limited to the solubility of the desired ingredients in the wax. An additional limitation of this traditional coating approach is that the flavor remains trapped inside the wax and is not available to the oral cavity or interproximal spaces during flossing. Even if the wax is mechanically removed from the floss or tape by flossing very little of the wax-trapped ingredient content makes contact with the oral cavity. In spite of the great sensitivity of taste buds and olfactory nerves, these “trapped” flavors are barely perceptible.
Hill et al. disclose a series of coating agents for multifilament dental flosses as distinguished from monofilament tapes (see U.S. Pat. Nos. 4,911,927; 5,057,310; 5,098,711; 5,165,913 and 5,711,935). These coating agents basically rely on emulsifiable ingredient consisting of a suitable surfactant, such as a poloxamer (Pluronic F-127) and a “coating agent” which is insoluble in, but emulsifiable by the surfactant in its molten state. These coating agents are typically very non-polar materials such as silicones (PDMS) or microcrystalline paraffin waxes. The teachings of the Hill, et al. patents are incorporated herein by reference.
Despite the utility of the Hill et al. coatings, their multi-functionality and commercial use in major brands and specialty professional multifilament flosses, the greatest draw-back of these melt-emulsion systems is the inherent viscosity characteristic of any emulsion, especially melt emulsions. These high viscosities necessitate a manufacturing process requiring specialized equipment to force the high viscosity melt either down into the multifilaments of the floss by means of “compression loading”.
There are also many references and commercial embodiments of the use of so-called water soluble waxes, primarily high molecular weight polyethylene glycols (PEGs), to coat dental flosses and tapes. The primary function of the PEG is to serve as a saliva soluble carrier for small amounts of flavor and other additives. The advantage of a PEG coating is that its melt viscosity is low and low levels of coating can be added with very simple mechanisms requiring little need for attention by an operator. The most common of these is a simple rolling wheel, the lower one-third of which is immersed in the molten PEG, and the floss or tape is pulled across the top of the wheel, thereby picking up a small quantity of the molten PEG coating agent.
There are many shortcomings of the simple water-soluble wax (PEG) coated flosses and tapes. Among them:    (1) The products are slick and thus hard to hold (hand feel);    (2) The products lack surfactancy, i.e. the ability to clean in the interproximal spaces;    (3) The products have low coating loads due to the poor adhesion, or if thick layers or loads are applied, they bind poorly to the tape or filament surfaces and flake off easily in product manufacture, packaging and consumer use;    (4) The products use water soluble waxes which will solubilize in only a limited range, or limited quantities, of ingredients, since it has no polarity or surfactant properties;    (5) The products have no ability to promote a pleasant mouth feel as do the coatings references in the Hill et al. patents.